The only thing extreme about the misguided notion that weather and climate are becoming more extreme is that notion's popularity among the mass media, vice presidents, and those campaigning to the left of vice presidents.

Devastating drought one week. Major hurricanes the next. This season has been a fearmonger's dream. Nevermind record crop yields across the majority of America's farmland that is not among the mere 2.2 percent of the country that experienced extreme drought.

This is not top secret. In fact, WCR Chief Editor Patrick Michaels told Fox News recently that the much-ballyhooed "Drought of 1999" was highly localized and noted that nationally, precipitation was actually above normal. After which Fox suddenly decided not to air the interview.

Climate is not becoming more extreme. Ken Kunkel, Roger Pielke Jr., and Stanley Changnon recently completed a comprehensive review of extreme weather in the United States. They used a two-pronged approach. First, they looked for trends in losses/damage/casualties from the weather event in question; then they determined if the physical measures were changing in the same manner. For example, if the strength or frequency of landfalling hurricanes has been steady but hurricane losses are going through the roof (no pun intended), this is not a global warming problem, it's a too-many-people-making-too-much-money-and-buying-beachfront-property problem! The only way to put a stop to this fiscal independence and prosperity is to implement some taxing vehicle like the Kyoto Protocol.

All it takes is a little logic, a few facts, and a willingness on the part of the media to stop telling people what they think we want to hear. Which will make for some slow news days indeed. For the record, here's the scoop on all your favorite weather and climate disasters.

Hurricanes

Loss of life from hurricanes has decreased since the beginning of this century, but damage has increased tremendously. Since World War II (when hurricane records are most reliable), the number of landfalling hurricanes has declined, while the intensity has been steady. After "normalizing" for inflation, income, and coastal population, tropical cyclones are actually having less impact now than they did in earlier parts of the century (Figure 1).

Figure 1.  Hurricane damage costs, 1930 to present (in 1995 dollars).  After "normalizing" for inflation, income, and coastal population, tropical cyclones are actually having less impact now than they did in earlier parts of this century.

Thunderstorms

Though they are essential rain-producers in most of the United States, thunderstorms are responsible for 45 percent of all weather-related losses to insured property. Using the insurance industry definition of a "catastrophe" (an event causing at least $5 million in losses), Kunkel compared catastrophic losses with thunderstorm days for five-year periods across the nation (Figure 2). "Catastrophes" are going up—but thunderstorms are steady. According to the authors, "The curves suggest that the increase in catastrophes and the losses they represent over time are not a result of shifts in thunderstorm conditions but rather a function of other factors such as increasing population and the associated property at risk to such events." It's that too-much-money thing again.

Figure 2.  Catastrophic ($5 million-plus) losses vs. thunderstorm days for five-year periods across the United States.  Catastrophes are going up—but thunderstorms are steady.

Hail

There are 20 to 25 hail-induced catastrophes every five years. Hail losses—mainly to crops—in the United States have remained steady (when expressed in terms of annual losses per five-year period) since 1950. Again, no trend.

Tornadoes

Let's see if you've been paying attention. Fill in the blanks: The number of deaths from tornadoes is going [up/down] while the number of tornadoes observed is going [up/down]. If you said "down" and "up" then you could have a promising future as a climatologist! That's right—we're finding a lot more of 'em and we're gettin' outta the way faster.

Winter storms

Kunkel cited a study by WCR Associate Editor Robert Davis and colleagues noting an increase in the number of severe Atlantic coastal storms. Winter storms (nor'easters) have been more common along the eastern seaboard, and damage has increased significantly in the 1990s. But consider the global warming angle: A key ingredient in the formation of major nor'easters is a strong temperature contrast along the southeastern coast. In other words, the colder the air in place over the mid-Atlantic and South, the stronger the storm. "Global warming" has allegedly warmed the high latitudes in winter, so it's hard to associate the increase in storm intensity with pernicious industrial activity.

Heat waves and mortality

About 10 years ago, Kalkstein and Davis evaluated summer and winter mortality by identifying "threshold temperatures" for each major city. This is the temperature beyond which mortality tends to increase significantly. Based on these thresholds, Kunkel calculated threshold exceedences and the number of four-day heat waves per station (Figure 3). Aside from the occasional peak, there is no trend, and the 1930s stand out as a very hot period. There is likewise no trend in low temperature exceedences and cold spells (Figure 4).

Figure 3.  Heat waves, 1930 to present.  Aside from the occasional peak, there is no heat wave trend; the 1930s stand out as a very hot period.

Figure 4.  Cold waves, 1930 to present.  No trend exists in low temperature exceedences and cold spells.

The silver lining

In general, losses related to weather have indeed peaked in the 1990s in the United States. But they have not been accompanied by increases in the intensity or frequencies of the events themselves. Writes Kunkel:

"The results of the review strongly suggest that the increasing financial losses from weather extremes are primarily due to a variety of societal changes. These include population growth along the coasts and in large cities, an overall increased population, more wealth and expensive holdings subject to damage, and lifestyle and demographic changes exposing lives and property to greater risk."

None of this should be surprising. As people make more money they buy more things and the country makes/imports/ transports/sells more things, which in turn fuels the economy. To protect their things, people buy more insurance to make certain they recover their losses should foul weather strike. This is simple, as long as the government stays out of the weather insurance business. There's neither the need, nor the factual basis, to blame global warming for increased damage costs.

References:

Kunkel, K.E., et al., Temporal fluctuations in weather and climate extremes that cause economic and human health impacts: A review, Bulletin of the American Meteorological Society, 80, 1077–1098.

Davis, R.E., et al, 1993, Synoptic climatology of Atlantic coast northeasters. International Journal of Climatology, 13, 171–189.